Friedrich krecke and ignaz rosenberg



U ITED STAT S PAT/ENT OF IC FRIEDRICH KRECKE AND IGNAZ ROSENBERG, O1 BIEBRICH, GERMANY. ASSIGNORS TO KALLE & (0, OF SAME PLACE.

AMIDONAPHTHOLDISUL FO-ACID K.

SPECIFICATION forming part of Letters Patent No. 563,382, dated July 7, 1896. I Application filed. December 30, 1895. Serialllu. 573,812. lspecimenal Patented in England January 9, 1894,No. 515.

ters Patent in England, No. 515, dated J anu-' My 9, 1894,) of which the following is a specification.

This invention relates to the manufac-.

ture of anew amidonaphtholdisulfo-acid-the 1. 8.4. 6. amidonaphtholdisulfo acid which forms valuable azo dyes for cotton and wool when treated in various manners with diazo and tetrazo bodies.

In order to prepare this new naphthalene derivative we proceed as follows: We stir ten parts of 1.5. naphthalene disultonate of sodium into forty parts of sulfuric monohydrate, add nine parts of fuming sulfuric acid 1 containing seventy per cent. SO at a temperature not above 40 centigrade, and heat the.

sulfo-acid is'then' cooled and nitrified with 3.3 parts nitric acid containing seventy per cent. HNO at a temperature not above centigrade. After some hours agitation at this temperature the nitration is finished. Now we stir the whole mass into five times its weight of water and reduce the formed 1.4. 6.8. nitronaphthalenetrisulfo-acid by addition of iron-filings. Then we neutralize with lime, filter ofi the calcium sulfate, convert the calcium salt into the sodium salt, and acidity the solution with hydrochloric acid. On cooling, the acid sodium salt of the naphthylamintrisulfo-acid crystallizes out in fine white needles. This precipitate is heated in an autoclave, which is fitted with an agitator, with twice its weight of caustic-soda lye of 50 Baum for ten to twelve hours up to temperatures between 160 and 170 centigrade. The produced alkaline liquid is aciduacid separates 011 cooling, is filtered off and pressed. In this state it can'directly be used for color-making. The above-described melting process "with caustic soda can also be performed in an open vessel.

The so-produced new amidonaphtholdisult'oacid which we call K acid diifers from the 1. 8.3. 6 amidonaphtholdisulfo-acid called ll acid in many ways. First, it is produced in a difierent manner, and, besides, it shows different properties. ble in water and gives on the whole azo colors It is much easier solu which are more reddish in shade than those prepared with H acid. Perhaps in consequence of its greater solubility in water, perhaps on account of its difierent constitution, our K acid reacts inuch quicker in acid solution with diazo bodies than the H acid. colors made with K acid can on the whole be salted out much easier, have greater inclination to crystallize, and dye shades of greater depth than those made with H acid.

' The-1.8.4.6. naphthylamintrisulfo-acid,

from which our K acid is made by treatment with caustic soda at high temperatures, forms with nitrous acid a diazo body, which cannot be precipitated from its aqueous solutions by addition of common salt; while the diazo compound of the 1.8.3.6. naphthylamintri sulfo-acid, from which the II acid is derived, 'can be easily salted out.

From our new 1.8.4.6. amidonaphtholdisulfo-acidfour classes of azo colors can be made. Y

First. Primary azo colors which are made by acting on K acid with a molecular prop0rtion of a diazo body. As an example we give the combination of diazo benzene with K acid, which dyes a bright red on wool from an acid bath.

Second. Disazo colors which are made by combining one molecule of K acid with one molecule of a diazo body in acid solution and.

acting with two molecules of K. acid on one a bright violet blue on unmordanted cottonJ Fourth. Mixed tetrazo colors which are made by acting with one molecule of K acid on intermediate combinations of one molecule of a tetrazo body with one ,molecule of an aromatic amin or a phenol or sulfo or carbo ac ds of such compounds or by acting on combinations of one molecule of, K acid and one molecule'of a tetrazo body with an aromatic amin or phenol or sulfo or carbo acids thereof. Example: The combination of tetraz'o-dimethoxydiphenyl with one molecular proportion of K acid and one of H acid, which dyes a pure greenish blue on unmordanted cotton.

hat we claim is 1. The process of making 1.8.4.6 amidonaphtholdisulfo-acid, which consists in sulfonating 1.5 naphthalenedisulfo-acid with fuming sulfuric acid at temperatures not above that which can be attained by heating on a water-bath; transforming the so-produced 1.3.5 naphthalenetrisulfo-acid by nitration and reduction into the 1.4. 6.8 naphthylamintrisulfon ic acid, the diazo derivative of which cannot be precipitated from its aqueous solutions by common salt, heating this naph- 3o thylamintrisulfo-acid with caustic-soda lye, and precipitating it as acid sodium salt from the alkaline-liquid thus obtained by acidula tion with muriatic acid.

2. As a new product, the 1.8.aL6 amido- 35 naphtholdisulfo-acid K, which is readily soluble in water and gives azo colors which are more reddish in shade than those prepared with the H acid; it reacts much more readily in acid solution with'diazo bodies; the colors 40 made with the K acid are more readily salted out, havegreater tendency to crystallize, and dye shades of greater depth than those made with the H acid.

In testimony whereof we have signed our 45 names to this specification in the presence of two subscribing Witnesses.

' FRIEDRICH KRECKE.

IGNAZ ROSENBERG. Witnesses:

ROBERT DORFELDER. CARL ED. I'IAHN. 

